<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            padding: 0;
            margin: 0;
        }
        .a{
            width: 300px;
            height: 300px;
            background-color: blue;
        }
        div:nth-child(2){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(192, 125, 24);
        }
        div:nth-child(2){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(235, 16, 16);
        }
        div:nth-child(3){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(132, 204, 15);
        }
        div:nth-child(4){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(240, 10, 125);
        }
        div:nth-child(5){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(69, 11, 228);
        }
        div:nth-child(6){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(82, 10, 177);
        }
        div:nth-child(7){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(12, 212, 146);
        }
        div:nth-child(8){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(221, 76, 9);
        }
        div:nth-child(9){
            width: 100px;
            height: 100px;
            float: left;
            background-color: rgb(68, 30, 38);
        }
    </style>
</head>
<body>
    <div class="a">
        <div>
            <p>1</p>
        </div>
        <div>
            <p>2</p>
        </div>
        <div>
            <p>3</p>
        </div>
        <div>
            <p>4</p>
        </div>
        <div>
            <p>5</p>
        </div>
        <div>
            <p>6</p>
        </div>
        <div>
            <p>7</p>
        </div>
        <div>
            <p>8</p>
        </div>
        <div>
            <p>9</p>
        </div>
    </div>
</body>
</html>